Valves activated by electrically active polymers or by shape-memory materials, device containing same and method for using same

ABSTRACT

This invention concerns a valve ( 2 ), with at least one channel ( 3 ) running through it, allowing a fluid (F 3 ) to be directed by transfer means within a device ( 1 ), the device ( 1 ) featuring at least one face ( 4 ), possibly flat, the valve ( 2 ) consisting of a film ( 7  or  16 ), flexible and/or which can be deformed, fixed on all or part of the face ( 4 ) of said device ( 1 ), and a film actuator ( 7 ), which enables said valve ( 2 ) to be activated or deactivated, this actuator consisting of an electrical power source.  
     It also consists of a test sample card ( 1 ) equipped with at least one valve ( 2 ), and a process for actuating the valve ( 2 ), as described above.  
     The invention is particularly applicable in the field of diagnosis.

[0001] This invention concerns the field of micromanipulations of fluidswherein valves are used to direct at least one fluid displaced bytransfer systems within a test sample card.

[0002] Up until now, most test sample cards have recesses on both oftheir plane and parallel faces as well as crosswise recesses, all of therecesses forming a channel network in which one or more fluids aredisplaced. On the face of the cards, said recesses are marked out byadhesive films. Fluid displacement is controlled by valves.

[0003] This type of structure is not reusable, as a valve can only beused efficiently once. Thus, when the valve is tipped into closedposition, the adhesive surface of the film also comes into contact withthe rest of the card, and the valve can therefore no longer be used. Thevalve remains in closed position.

[0004] The only solution to this problem thus consists in depositing aninert non-adhesive layer onto an adhesive film, this inert layer beinginitially made by means of cut-outs, for example by using a punch, andpositioned accurately in relation to the adhesive film.

[0005] Technically speaking, this is not easy to achieve. In addition,the cost of manufacturing such complex film as well as the difficultiesencountered in positioning the film on the test sample card areincompatible with mass production.

[0006] Patent application WO-A-00/13795, filed by the applicant,describes an invention on a device or test sample card inside which areaction or at least two parallel or series reactions can be carriedout. The device consists of a network of channels wherein the transferof at least one sample to be treated and/or analyzed is possible, on theone hand, and at least one valve built into the device, on the otherhand, enabling the orientation of each sample transferred at the networklevel and thus the control of transfers, reactions and analyses in saiddevice. In the embodiment shown in FIGS. 1 through 3, it can be seenthat an elastomer disk is inserted between the adhesive film and thebody of the card, which allows the valve to be reused.

[0007] This structure thus provides a solution, although it increasesthe number of elements and the manufacturing cost of a functional testsample card.

[0008] Document WO-A-97/27324 attempts to provide a solution to thisproblem. Thus, it concerns a cassette to conduct reactions in parallelwhich features an entry and exit orifice to transfer the sample(s) to beintroduced into the cassette. Valves are present at cassette level,which have a particular construction (Bursapak chamber, piston valve,bead valve). Under a continuous outside force, these valves allow achannel to be held closed. In this embodiment, the film is heat-sealedto the cassette.

[0009] However, this construction has a major disadvantage. Thedisadvantage resides in the deformation of the face of the cassette ontowhich the film is heat-sealed. While this face is originally plane, theheat-sealing weld causes distortion which is detrimental to subsequentproper use of the cassette. This could range from an error inmanipulation and/or analysis to rendering the valves inoperable. Theworst problems may be encountered when this type of cassette is used byan automated controller, which is generally the case. In thisconfiguration, the card, which is warped by the heat-seal, may block oreven damage the automated controller assembly.

[0010] Another disadvantage of this innovation is that it is absolutelynecessary that the film is precisely heat-sealed onto the card. Even atiny error may lead to channel blockage and/or valve leakage.

[0011] The applicant also filed a patent application PCT/FR00/1719,filed under priority Jun. 22, 1999, which provides a practical responseto all of the disadvantages of prior art described above. Thus, the filmis heat-sealed onto the body of the test sample card without damagingthe surface where the heat-seal is made. Furthermore, the tolerance forthe heat-sealing position is greater, as it only outlines the area thatmakes up the valve and does not follow it closely. This inventionconcerns a valve, with at least one channel running through it, allowingat least one fluid displaced by transfer means within a test samplecard, the card featuring two faces connected to one another by an edge,characterized in that it consists of a film, which is flexible and/orwhich can be deformed, secured partly on at least one of the faces ofsaid card, and a film compression means which can be activated ordeactivated. The film is secured to at least one of the plane faces byfixing means located at the level of a recession peripheral to thevalve, such as a groove. In addition, fixation is carried out by a heatseal peripheral to the valve in the bottom of the groove.

[0012] However, the flexible films used in prior art are inert, i.e.they only have structural deformations when subjected to physicalstresses. The succession of these stresses, as well as their intensity,may induce constant deformation, which could lead to definitive closingor opening. In addition, these openings and/or closings by deformationrequire a mechanism to actuate the movement of flexible films, which isbulky, complicated and costly.

[0013] Films exist which are not inert. Such films are intrinsicconducting polymers, which will be defined in more detail below. The useof such films as actuators is also known as shown by the followingpatent applications:

[0014] WO-A-99/07997 concerning a rotary motor driven by a conductingpolymer,

[0015] EP-A-0.735.518 which describes a Braille module featuring anactuator which contains a polymer with intrinsic electricalconductivity, and

[0016] WO-A-98/35529 featuring a sonic actuator with elastomerdielectric polymer film.

[0017] Patent application WO-A-97/22825 describes a microfluid devicedesigned to deliver or not deliver a liquid or gas contained in a pocketvia a conduit (48). The opening or closing of the conduit, thepartitions of which are flexible, is carried out by a valve using apiezo-electric actuator which can close or open the conduit by means ofa metal strip. The valve is opened or closed according to the electricpower applied to the actuator. Likewise, U.S. Pat. No. 6,033,191concerns a pump and not actually a valve. In addition, this pumpfeatures a piezo-electric actuator which is superimposed on the pumpmembrane and even secured by means of a conductive bonding agent.

[0018] In contrast to this invention, where the actuator is only theelectrical current that will directly deform the film, the actuatoraccording to prior art, constituted by the two previous documents, ismade of two parts, which undergo either directly, for the piezo-electricpart, or indirectly, for the metal strip, the electric potential, thesetwo parts being independent from the partition which, as for it, isalways deformed under the indirect action of the electrical current.

[0019] In accordance with this invention, the use of conductingpolymers, also known as electroactive polymers, which are very differentfrom those mentioned above, is foreseen. They are used to make valvesand, more specifically, mini-valves, which are normally open or closedand which close or open, respectively, when electrical current isapplied to them. This mechanism considerably simplifies their design andoperation.

[0020] Such polymers are already known, but their use is currentlylimited to fundamental research. The use of these materials in valves onsmall test sample cards is thus of special interest and not obvious.

[0021] In relation to mechanically- or pneumatically-controlled valves,valves controlled by electroactive polymers or shape-memory materialshave the following advantages:

[0022] a reduction in the instrumentation associated with valveaddressing,

[0023] miniaturization is facilitated: a valve can be one micrometer(μm) in size, and thereby a larger density of valves can be obtained,which enables more complex biological protocols to be managed, with moresteps for example, and

[0024] association of at least two valves along the same channel, which,through rigorous control of their opening and closing, may enable amicro-pump to be created.

[0025] Within the scope of the micro-pump, there is a need to perfectlysynchronize the opening and closing of both valves concerned, which canbe performed electrically, although much more difficult mechanically,particularly with dimensions in the order of a few micrometers.

[0026] To that end, this invention concerns a valve with at least onechannel running through it, allowing a fluid to be directed by transfermeans within a device, the device featuring at least one face, possiblyflat, the valve consisting of a film which is flexible and/or can bedeformed, fixed on all or part of the face of said device, and a filmactuator, which enables said valve to be activated or deactivated, thisactuator consisting of an electrical current source.

[0027] Preferably, the device is a test sample card with two faces,possibly flat and connected to one another by an edge, the valveconsisting of a film which is flexible and/or can be deformed, fixed onall or part of at least one of the faces.

[0028] Preferably, the actuator acts directly on an electroactivepolymer or on a shape memory material.

[0029] According to a first alternate embodiment, the film consists ofat least one layer of electroactive polymer allowing the valve to beactivated or deactivated directly.

[0030] According to this first variant, a first embodiment isrepresented by the film which consists of a layer of electroactivepolymer associated with one porous membrane coated on the other of itsfaces with a metallic layer of gold or silver, the electroactive polymerforming the positive electrode or the negative electrode and the metallayer forming the actuator's opposite polarity electrode or theelectrical power source.

[0031] According to this first variant, a second embodiment isrepresented by the film which consists of a layer of electroactivepolymer associated with one porous membrane coated on the other of itsfaces with a metallic layer of gold or silver, the electroactive polymerforming the positive electrode or the negative electrode and the metallayer forming the actuator's opposite polarity electrode or theelectrical power source.

[0032] In these two embodiments, a layer of electroactive polymerconsists of polyaniline and/or polypyrrole and/or polythiophene and/orpolyparaphenylvylene and/or poly-(p-pyridyl vinylene), possiblyassociated with polyethylene.

[0033] Still regarding these two embodiments, the porous layer is anymaterial or mix of materials whose porosity allows ions to pass throughit, such as Teflon, polyamide, cellulose, polyaceate and/orpolycarbonate.

[0034] According to a second alternate embodiment, a control mechanismis present between the film and the actuator.

[0035] According to this second variant, the control mechanism consistsin whole or in part of an electroactive polymer as defined above, or ofa shape memory material, enabling the valve to be activated ordeactivated indirectly.

[0036] When using an electroactive polymer, the electroactive polymerconsists of a longitudinal strip of at least one layer of electroactivepolymer. When using a shape memory material, it consists of a complexalloy whose structure changes according to the temperature, such as anickel and titanium alloy.

[0037] In addition, according to the second alternate embodiment, theshape memory material cooperates with a rocking lever to form all orpart of the control mechanism.

[0038] More specifically, the rocking lever consists of a flexible partand a rigid part, the rigid part cooperating with a valve compressionmeans, the shape memory material, the lever and the compression meanstogether forming the control mechanism.

[0039] This invention also concerns a test sample card containing atleast one valve, such as described above.

[0040] The invention finally proposes a valve actuating process, asdescribed above, which consists in:

[0041] applying an electric current to an electroactive polymer film orwire, or to a shape memory metal in rest position, the valve being inopen (or closed) position,

[0042] maintaining the current to hold the film or wire in activeposition corresponding to a direct or indirect action on the valve inclosed (or open) position, and

[0043] stopping the current so that said film or wire returns to restposition and said valve returns to open (or closed) position.

[0044] The accompanying drawings are given by way of example and are notto be taken as limiting in any way. They are designed to make theinvention easier to understand.

[0045]FIG. 1 represents a top view of the test sample card, according toa first embodiment.

[0046]FIG. 2 represents a cross-sectional view along A-A of FIG. 1, whenthe valve is in closed position.

[0047]FIG. 3 represents a cross-sectional view identical to FIG. 2, whenthe valve is in open position.

[0048]FIG. 4 represents a view similar to FIG. 3, i.e. when the valve isin open position, in a second embodiment.

[0049]FIG. 5 represents a view identical to FIG. 4, when the valve is inclosed position.

[0050]FIG. 6 represents a top view of FIGS. 4 and 5.

[0051]FIG. 7 represents a view similar to FIGS. 3 and 4, i.e. when thevalve is in open position, in a third embodiment.

[0052]FIG. 8 represents a view identical to FIG. 7, when the valve is inclosed position.

[0053]FIG. 9 represents a perspective view of a test sample cardaccording to a fourth embodiment of the invention.

[0054]FIG. 10 represents a cross-sectional view along B-B of FIG. 9,when the valve is in closed position.

[0055]FIG. 11 represents a cross-sectional view identical to FIG. 10,when the valve is in open position.

[0056]FIG. 12 represents a top view of a set of test sample cards, in apartial view, according to FIGS. 10 and 11, in which all the visiblevalves are in closed position.

[0057]FIG. 13 represents a view identical to FIG. 12, in which only oneof the visible valves is in open position.

[0058]FIG. 14 represents a view similar to FIG. 12, although in whichall the visible valves in closed position are directly closed by therocking lever.

[0059] Finally, FIG. 15 represents a view identical to FIG. 14, in whichonly one of the visible valves is in open position.

[0060] The Test Sample Card According to the Invention

[0061] A test sample card 1 according to the invention is a combinationof functions featuring fluid management (micro-fluids), chemical and/orbiochemical reactions, separation of species present in the fluid anddetection of these species, grouped together on the same supportmeasuring just a few square centimeters (cm²) in size. These systems canbe used to automatically and autonomously perform all the functions ofthe entire traditional chemical and/or biochemical analysis process byhandling only very small quantities of reagent, between a fewmicroliters and a few nanoliters.

[0062] The most routinely encountered functions for this type of testsample card 1 are represented in table 1 below. This list is in no waycomprehensive. TABLE 1 Main functions used on the test sample cardsaccording to the invention Fluid management Reaction SeparationDetection Electrophoresis Mixing Electrophoresis ElectrochemistryElectroosmosis Incubation Electroosmosis Spectroscopy MicropumpingHeating Chromatography Microvalve Sensor

[0063] Silicon, polymers, quartz and glass can be used to make thesetest sample cards. Conducting polymers and electroactive polymers,defined below, are suitable for numerous other functions.

[0064] This invention concerns a reaction card 1 which consists of arectangular parallelepiped featuring a front surface 4 and a rearsurface 5 connected together by an edge, also referred to as the side 6.All of the elements which form the front surface 4 are represented insolid lines in FIG. 1. In addition, a certain number of through channels3 can be noted on this surface 4. These channels 3 are partitioned by atransparent film 7, affixed on said front surface 4. Nonetheless, it isnot mandatory that this film 7 be transparent, as those which will bedescribed below; it may be opaque, translucent, etc. In addition, thetransparent nature allows better viewing of the position of thebiological solution being tested, or any other solution introduced intothe card 1. The rear surface 5 also features a transparent film 21 whichpartitions the channels 3 shown as dotted lines, because they are flushwith this rear face 5 in some locations. This film 21 is very similar tothat represented on the front face 4 of FIGS. 10 and 11, which formsanother embodiment, and bears the reference 16. These films 16 and 21consist of BOPP (Biaxially Oriented PolyPropylene) films or other filmsof the same type, which are soldered or bonded to the body of the card1, this body being inert in relation to the solutions transferred or tothe reactions undergone. The nature of the film 7 however is ratherspecial as it is made of an electroactive polymer. It will be discussedin further detail later on.

[0065] Each film 7, 16 or 21 may be present on the entire surface of thecard 1. This is the case for films 16 and 21, or on certain portions ofsaid card 1, as for the film 7. Nevertheless, the film 21 may bemissing. In this case it is replaced by a partition made with the samematerial as the rest of the body of the card 1.

[0066] The film 16 defines the outer face of the valves 2 according tothe embodiment shown in FIGS. 10 and 11. This film 16 is thussufficiently flexible to allow a test liquid, a treated liquid, a washsolution, or an elution liquid, etc. to pass through it. It may consistof a silicone, latex or elastomer membrane, for example Santopren(registered trademark), complex two-thickness sandwich films, such as acombination made of PE/PET (PolyEthylene/PolyEthylene Tetraphtalate) forexample, or complex sandwich films with more than two layers, such as acombination made of SEBS/SBS (Styrene Ethylene/Butylene Styrene/StyreneButylene Styrene).

[0067] In addition, the transparent film 16 located on the front 4, andthe transparent film 21 located on the rear face 5, can consist of asingle transparent film, which further facilitates the fabrication ofsuch a card 1 which is so equipped.

[0068] A test sample card 1, according to the invention, generallyfeatures dozens of valves 2, as is the case for example in patentapplications PCT/FR00/01718, filed under priority Jun. 22, 1999, andFR00/10978 of Aug. 28, 2000, filed by the applicant. An example of fluidmovements (F1 in FIG. 1) inside the channel network 3 or (F3 in FIGS. 3,4, 7 and 11) on the valves 2 are clearly disclosed in patent applicationFR00/10978.

[0069] These valves 2 are controlled by electronic addressing as will bedescribed below.

[0070] Conducting Polymers

[0071] For informational purposes, the conducting polymers discussed inthe prior art above, may be of three broad types:

[0072] extrinsic conducting polymers, which consist of an insulatingpolymeric matrix to which are added conducting particles, generallycarbon black, which ensures the electric conduction of the material; theextrinsic conducting polymers have numerous industrial applications inthe fields of packaging (anti-static or anti-electromagnetic),electrical protection and connector technology,

[0073] ionic conducting polymers, which can be classified among polymershaving ionic groups, the polymers swelled with ionic solution and thesolid polymer electrolytes; the polymer's conductivity is ensured by theions present in the material; in industry, ionic conducting polymers areused in polymer electrochemical generators,

[0074] intrinsic conducting polymers, which present an alternation ofsingle and double bond (conjugated polymer); this special electronicstructure is responsible for their conducting properties, the conductionbeing ensured by the polymer's hydrocarboned chains; certain haveelectric properties (polyaniline, polypyrrole, polythiophene,polyacetylene) while other have electroluminescent properties(polyphenylene vinylene).

[0075] Electroactive Polymers

[0076] Electroactive polymers deform when a voltage is applied to them.They can be divided into two families responding to an electric voltageby either a pendulum movement or by a longitudinal movement, as shown intable 2 below. TABLE 2 The nature of electroactive polymers according totheir displacement mode Displacement mode Pendulum Longitudinal IonicPolymer Metal Electrostrictive Polymer Composite (IPMC) Piezo-electrictype Dual-layer/Multilayer Electrostatic Polypyrrole, polyaniline Ionicpolymer gel Material Carbon nanotubes, Shape Piezo-electric memoryalloys . . . ceramic . . .

[0077] Products exist in sheet form, such as Nafion (registeredtrademark), with a thickness of 180 μm, manufactured by DuPont deNemours in the United States. It is a perfluorosulfate polymer, which isthen covered with electrodes. Additional information about this materialcan be found in the article by S. G. Wax and R. R. Sands, ElectroactivePolymer Actuators and Devices. SPIE Vol. 3669, March 1999; 2-10, or inthe article by Y. Bar-Cohen, S. Leary, M. Shahinpoor, J. O. Harrison andJ. Smith, Electroactive Polymer (EAP) actuators for planetaryapplications. SPIE Vol. 3669, March 1999; 57-63. Protons are exchangedfor mobile cations used in the exchange process, which are generallysodium (Na⁺) or lithium (Li⁺). It requires the presence of a solvent tooperate and absorbs a large quantity of water. The SO₃ ⁻ groups arefixed to the matrix of the membrane.

[0078] Electric Addressing

[0079] Concerning the problem of electronic addressing of a matrix ofn×n electrodes, corresponding to electroactive valves, present on a testsample card, a direct connection or multiplexing technique can be used.

[0080] The direct connection is the simplest addressing configuration.Each element of the X/Y matrix is connected by two connecting wires. Thesupport can be either a silicon or polymer of variable size owing tomicro-technologies and printed circuit and screen-printing techniques.

[0081] The multiplexing technique consists in integrating electronicfunctions under the electrodes of the matrix (column-line decoder).Depending on the line and column selected, these electronic functionsenable a point X/Y to be addressed specifically. Only micro-electronictechniques enable components having electronic functions to be made.This type of addressing configuration, based on integrated circuittechnologies, is reserved for small components made only on silicon orglass. Such multiplexing principles are well described in U.S. Pat. No.5,965,452, for example.

[0082] The choice of an addressing configuration depends on the foreseennumber of electrodes per cm². For more than 100 electrodes per cm², amatrix multiplexed by micro-electronic techniques on silicon or glass isgenerally used. This technique, owing to its low cost per cm², must belimited to small components, in the order of a few mm², and is suitablefor making electrically-addressable DNA chips. On the other hand, forlesser densities, the direct connection configuration may be used.

DETAILED DESCRIPTION OF THE INVENTION

[0083] FIGS. 1 to 8 represent a first embodiment using an electroactivepolymer film 7, which enables the electrical current to act directly onsaid film 7. These figures show three different constructionalternatives, represented in FIGS. 1 to 3 for the first alternateembodiment, in FIGS. 4 to 6 for the second alternate embodiment, and inFIGS. 7 and 8 for the third alternate embodiment, respectively.

[0084] FIGS. 9 to 13 represent a second embodiment which uses a normalfilm 16, i.e. identical to the film 21 located on the back 5 of the card1, and which allows the electric current source to act directly on saidfilm 16, via an intermediate control mechanism 13. These figuresdescribe a fourth alternate embodiment.

[0085] Following this description, reference to the alternateembodiments will be made in relation to the explanations provided above.

[0086] This invention concerns a test sample card 1 which is a smallmachined support, measuring a few square centimeters for example, andwhich, using a fluid circulation network, enables chemical or biologicalreactions (mixing, incubation, heating . . . ) to be managed(electrophoresis, pumping, valves, sensors, for example) and enables oneor more species present in a fluid to be separated (electrophoresis,chromatography, etc.) or detected (spectroscopic, electrochemicaldetection . . . ).

[0087] 1°) First Alternate Embodiment

[0088]FIG. 1 represents a first alternate embodiment which broadlyshares the characteristics of FIGS. 4 to 6 described in patentapplication PCT/FR00/01719 filed by the applicant under priority Jun.22, 1999, except that in the figures of this invention, there is noflexible tab. In this case, it can be seen that each valve 2 consists ofa small flat surface located at the same level as the rest of the flatsurface of said card 1 (see also FIGS. 2 and 3). This small flat surfaceincludes at least one inlet channel 3 and one outlet channel 3, theintersection between this surface and the fluid inlet and outletchannels 3 being in contact with the film 7 as is clearly shown in FIG.2. In this case, the valve is closed. It can be seen from FIG. 2 thatthe film 7 features an invagination 25, designed to block one of the twochannels 3. Of course, invaginations 25 can also block the other channel3 or both channels 3 of each valve 2. In addition, at the level of valve2, there may be more channels 3, that is three or more.

[0089] It should also be noted that the card features a number ofcompartments 17. The compartments 17 are connected to the valves bymeans of channels 3 and it is also possible, although not represented inthe figure, that other valves and other compartments are located on therest of the card 1 which allows mixing between two networks of channels3 located in parallel and not in series.

[0090] In FIGS. 2 and 3, it can be seen that, on the upper valve 4 ofcard 1, at least at the level of valve 2, there is a flexible film 7which is not self-adhesive, as explained in the section dealing withbackground art. This film 7 is thus heat-sealed in the peripheral groove9 around the valve 2. This special technique is described here by way ofa typical example of an embodiment and is not to be taken as in any waylimiting. Furthermore, it is already well-described in patentapplication PCT/FR00/01719. Nevertheless, on the lower face 5 of saidcard 1, a self-adhesive film 21, well known in prior art, can be used.Of course, depending on the fact that valves 2 are located on one sideor on both sides of card 1, it is also possible that a second flexiblefilm 7 is present on this other side. The upper 4 and lower 5 faces areconnected to one another by an edge 6.

[0091] The fluid or fluids in the test sample card 1 are displaced inthe direction F1 within this card 1 by means of a pressure or vacuumthat is created. Deforming the invagination 25 along F2, by applyingelectric voltage causing the ions to move in the conducting polymerfilm, authorizes the movement of the fluid at a valve 2, along F3 inFIG. 3. This ion mobility causes the deformation, the contraction or theexpansion of the film as a result of the displacement of watermolecules. The voltage-current response is typically voltamogramme whichfeatures significant hysteresis between the oxidation and the reduction.An example of the evolution of the current depending on the voltageapplied may be found, for example, in the article by T. W. Lewis, L. A.P. Kane-Maguire, A. S. Hutchinson, G. M. Spinks and G. G. Wallace,Development of an all-polymer, axial force electrochemical actuator.Synthetic Metals 102 (1999) 1317-1318.

[0092] In this manner, the film 7 can be distorted and the fluid canmove in the direction of F3 as is clearly displayed. The film 7 musttherefore be made of a material that deforms under the action of thiselectric current and that returns to blocking position according to FIG.2, as soon as said current is no longer applied.

[0093] According to a first construction method, the electroactivepolymer forming the film 7 consists of a porous membrane coated on oneof its faces with a layer of gold or silver, forming both the positiveand negative electrodes of the electric current source.

[0094] According to a second construction method, the electroactivepolymer consists of a porous membrane with each of its faces coated witha conductive layer, one layer forming the positive electrode and theother layer forming the negative electrode of the electric currentsource.

[0095] This conductive layer consists of polyaniline and/or polypyrrole,two materials which start a pendulum movement when electrically excited.

[0096] 2°) Second Alternate Embodiment

[0097] This variant shares the same components and thus the samereferences as those of the first variant, namely the valve 2, thechannels 3, the faces 4 and 5 of the test sample card 1, the edge 6 ofsaid card 1, the electroactive polymer film 7 on the face 4 of the card1, the recess or peripheral groove 9 around the valve 2, the peripheralweld 10 in the bottom of the groove 9 and the film 21.

[0098] However, the upper face 4 of the card 1 features a recess 26,whose dimensions (namely greater depth and diameter) allow:

[0099] the presence of thickening 27 (lesser depth and diameter) of thefilm 7, and

[0100] that the two channels 3 used in the valve 2 are open at the levelof this recess 26.

[0101] When a potential difference is applied, as defined above in thefirst alternate embodiment, the film 7 will be able to swell and fluidwill thus no longer move in the direction of F3 as can be clearly seenin FIG. 5. It is therefore necessary that the film 7 be made of amaterial that deforms under the action of this electric current and thatreturns to position to allow the fluid to move in the direction of F3,see FIG. 4, as soon as said current is no longer applied.

[0102] It is thus the opposite effect of the first alternate embodiment,when an electric current is applied, the valve 2, according to thisfirst alternate embodiment, is open while the valve 2 is closedaccording to the second alternate embodiment, and vice versa.

[0103] Of course, the recess 26 has a smaller diameter at the flat partcircumscribed by the peripheral groove 9.

[0104] 3°) Third Alternate Embodiment

[0105] This third variant shares the same components and thus the samereferences as those of the first and second variants, namely the valve2, the channels 3, the faces 4 and 5 of the test sample card 1, the edge6 of said card 1, the electroactive polymer film 7 borne by the face 4of the card 1, the peripheral groove 9 around the valve 2, theperipheral weld 10 in the bottom of the groove 9 and the film 21.

[0106] However, the upper face 4 of the card 1 features an internalspace 28, which is big enough so that the two channels 3 used in thevalve 2 open at the level of this internal space 28.

[0107] When a potential difference is applied as defined above in thefirst and second alternate embodiments, the film 7 can be distorted andfit the shape of the internal space 28, which will prevent the fluidfrom moving in the direction of F3 as can be clearly seen in FIG. 8. Itis therefore necessary that the film 7 be made of a material which isidentical to the first two alternate embodiments described above.

[0108] As soon as this electric current action stops, the film 7 returnsto its initial position, according to FIG. 7 and thus allows the fluidto flow in the direction of F3.

[0109] Of course, the reverse phenomenon is possible, that is that theelectroactive polymer 7 closes the valve 2 at rest, and opens said valve2 as soon as current is applied.

[0110] 4°) Fourth Alternate Embodiment

[0111]FIG. 9 represents a card 1 which is different from the previouscards even if it maintains the same reference. In this manner, this cardstands out by the absence of the electroactive polymer film 7 which isreplaced by a film 16, clearly shown in FIGS. 10 and 11, and whosecharacteristics are essentially mechanical, as mentioned above.

[0112] This fourth variant concerns a reaction card 1 which, like itspredecessors, consists of a rectangular parallelepiped featuring a frontface 4 and a rear face 5 connected together by an edge with a shoulder29.

[0113] A valve 2 is shown in greater detail in FIGS. 10 and 11. It canbe noted that at rest, the valve 2 is closed, as the film 16 is againstthe face where the channels 3, which form said valve 2, come out. Theclosed position is made possible by the presence of a compression meansor tab 8, fixed on the face 4 of the card 1 by part of its surface, theother part overhanging said valve 2. In order to ensure contact andperfect seal of the valve 2, an elastomer pin 11 borne by the tab 8ensures the connection at rest between said tab 8 and the film 16.

[0114] It can also be seen that there is a beveled face 12 at the freeend of the tab 8 which facilitates opening of said valve 2. This beveledface 12 is designed to allow said tab 8 to tip, in the direction of F4in FIG. 11, driven by an outside element, discussed below.

[0115] The manner in which this valve 2 operates is thus different fromthe three previous variants, as the electric current has no directaction on the film 16. If only the card 1 is observed, only the presenceor the absence of the tab 8, by means of its elastomer pin 11, allowsthe closing and opening of said valve 2 respectively.

[0116] The outside element implemented to allow the tab 8 to move in thedirection of F4 is represented in FIGS. 12 and 13. It is a controlmechanism 13 borne by the chassis 30 of an automated analysis apparatus,not shown in the figures. This chassis 30 includes at least one lever 15consisting of several parts:

[0117] a base 31 to secure it to said chassis 30,

[0118] a flexible part 18, forming an articulation axis with the nextpart 19,

[0119] a rigid part 19 to transmit the tipping movement along F6,

[0120] a bearing boss 20, the function of which will be explained lateron, and

[0121] an end 24, possibly beveled, which acts on the tab 8 (movement inthe direction of F4) and more specifically on the beveled face 12 ofthis tab 8.

[0122] This tipping along F6 is clearly shown in FIG. 13. It is producedby a wire made of shape memory material 22, with both ends in contactwith a connecting terminal 23 enabling addressing. In this manner, eachwire 22 is addressed and electrically positioned via a singletransistor, not shown in the figures, directly controlled by theinstrument's electronics. For this reason, a voltage in the order of oneto a few volts is applied to each connection terminal 23 in series,enabling addressing to take place, which causes the wire(s) 22 toexpand. If the wires 22 are in series, applying a voltage to terminal 23causes all of the wires 22 placed in series to expand. However, if eachterminal 23 electrically isolates the two electric wires 22 which areconnected to said terminal, the addressing can be carried out inrelation with all or part of these wires.

[0123] Along a wire 22, another contact exists with the bearing boss 20which acts as a means of transmission of the shrinking force F5 of saidwire 22, to ensure the tipping F6 of the rigid part 19 of the lever 15.Such wires 22 may consist of FLEXINOL wires (registered trademark) madeof a complex nickel-titanium alloy purchased from the DYNALLOY Inc.Company (Costa Mesa, Calif., United States of America). At ambienttemperature, this wire 22 is easily drawn, although when a sufficientcurrent flows through it, that is approximately 1,000 milliamperes (mA)at 0.3 Volt per centimeter (V/cm), its length decreases 3 to 5% whileexerting a traction force of approximately 900 gram.force (g.force).Nevertheless, this force depends on the diameter of the wire, as can beclearly seen in table 3 below: TABLE 3 Performance characteristics ofshape memory wires in relation to their diameter Wire diameter Shrinkingforce Relaxation force Typical current (mm) (g. force) (g. force) (mA)at 0.3 V/cm 0.05 35 8 50 0.10 150 28 180 0.15 330 62 400 0.25 930 1721000 0.38 2000 380 2500

[0124] The response times allow 13 to 65 cycles per minute, for atransition temperature of 90° C. The number of cycles shifts from 9 to40 if this temperature is 70° C. The life cycle of this type of wire 22is at least one million cycles.

[0125] As shown in FIGS. 12 and 13, the automatic analysis apparatus cancontain several cards 1 in parallel; these cards 1 could however also beinstalled in series, or both series and parallel at the same time. In anembodiment of the invention, the distance separating two cards 1 inparallel is 25 mm. Similarly, it is possible to have numerous levers 15above one another, in order to allow several valves 2 located side byside on a card 1 to be opened. The spacing which exists between twoadjacent levers 15 working on the same card 1 is generally between 1 and5 mm. Preferably, this spacing is a value used in the field ofelectronics, such as 3.96 mm, 2.54 mm or 1.28 mm.

[0126] 5°) Fifth Alternate Embodiment

[0127]FIGS. 14 and 15 represent a card 1 which is different from theprevious cards even if it maintains the same reference. In this manner,this card 1 stands out owing to the absence of the electroactive polymerfilm 7 which is replaced with a film 16, clearly shown in FIGS. 10 and11, and whose characteristics are essentially mechanical as mentionedabove. This fifth variant is a simplified evolution of the fourthvariant.

[0128] The fundamental difference lies in the fact that the card 1 doesnot have compression means 8. The card 1 thus has valves which arenormally open at rest, while they are normally closed in the fourthvariant.

[0129] The control mechanism 13 is thus simpler, according to this fifthvariant, as the lever 32 acts directly on said card 1; in this manner,the free end of the lever 32, not labeled, is equipped with an elastomerhermetic closing means or compression pin 33. This pin compresses thefilm 16 when the wire made of shape memory material 22, alreadydescribed in the previous variant, is not energized.

[0130] It is also possible to foresee that the wire 22 is replaced by alongitudinal strip made of electroactive polymer, according to the firstthree alternate embodiments.

References

[0131]1. Test sample card or device

[0132]2. Valve

[0133]3. Channel

[0134]4 and 5. Faces of the card (1)

[0135]6. Edge of the card (1)

[0136]7. Electroactive polymer film on the face 4 of the card 1

[0137]8. Compression means of the film 7 or flexible tab

[0138]9. Recession or groove peripheral to the valve 2

[0139]10. Peripheral weld located in the bottom of the groove 9

[0140]11. Elastomer hermetic closing means or compression pin borne bythe means or tab 8

[0141]12. Opening means or bevel borne by the means or tab 8

[0142]13. Control mechanism

[0143]14. Shape memory material forming the control mechanism 13

[0144]15. Rocking lever forming the control mechanism 13

[0145]16. Flexible film and/or which can be deformed, on the face 4 ofthe card 1

[0146]17. Compartment of the card 1

[0147]18. Flexible part of the lever 15

[0148]19. Rigid part of the lever 15

[0149]20. Bearing boss of the lever 15

[0150]21. Film on the other face 5 of the card 1

[0151]22. Wire made of shape memory material

[0152]23. Electric connection terminal for addressing purposes

[0153]24. Beveled end of the lever 15 acting on the tab 8

[0154]25. Invagination of the film 7

[0155]26. Recess on the face 4 of the card 1

[0156]27. Thickening 27 of the film 7 at the level of the recess 26

[0157]28. Internal space on the face 4 of the card 1

[0158]29. Shoulder of the test sample card 1

[0159]30. Frame of an automatic analysis apparatus

[0160]31. Base 31 of the lever 15 integral with the chassis 30

[0161]32. Rocking lever forming the control mechanism 13

[0162]33. Elastomer hermetic closing means or compression pin on thelever 32

[0163] F1. Fluid movements at the card 1 level

[0164] F2. Distortion of the film 7

[0165] F3. Fluid transfer at the valve 2 level

[0166] F4. Tipping of the tab 8

[0167] F5. Shrinking force of the wire made of shape memory material 22

[0168] F6. Rocking of the lever 15 driven by the wire made of shapememory material 20

1. A valve, with at least one channel (3) running through it, allowing afluid (F3) to be directed by transfer means within a device (1), thedevice (1) featuring at least one face (4), possibly flat, the valve (2)consisting of a film (7 or 16), flexible and/or which can be deformed,fixed on all or part of the face (4) of said device (1), and a filmactuator (7 or 16), which enables said valve (2) to be activated ordeactivated, this actuator consisting of an electrical power source,which acts directly on an electroactive polymer or on a shape memorymaterial.
 2. The valve, according to claim 1, characterized in that thedevice (1) is a test sample card (1) with two faces (4 and 5), possiblyflat and connected to one another (4 and 5) by an edge (6), the valve(2) consisting of a film (7 or 16), flexible and/or which may bedeformed, fixed on all or part of at least one of the faces (4 and/or5).
 3. The valve, according to either claim 1 or 2, characterized inthat the film (7) consists of at least one layer of electroactivepolymer enabling the valve (2) to be activated or deactivated directly.4. The valve, according to any one of claims 1 through 3, characterizedin that the film (7) consists of a layer of electroactive polymerassociated with at least one porous membrane coated on the other of itsfaces with a metallic layer of gold or silver, the electroactive polymerforming the positive electrode or the negative electrode and the metallayer forming the actuator's opposite polarity electrode or theelectrical current source.
 5. The valve, according to any of claims 1through 3, characterized in that the film (7) consists of a porousmembrane with each of its faces coated with an electroactive polymerlayer, one layer forming the positive electrode and the other layerforming the negative electrode of the electric current source.
 6. Thevalve, according to any one of claims 3 through 5, characterized in thata layer of electroactive polymer consists of polyaniline and/orpolypyrrole and/or polythiophene and/or polyparaphenylvylene and/orpoly-(p-pyridyl vinylene), possibly associated with polyethylene.
 7. Thevalve, according to any one of claims 3 through 5, characterized in thatthe porous layer is any material or mix of materials whose porosityallows ions to pass through it, such as Teflon, polyamide, cellulose,polyaceate and/or polycarbonate.
 8. The valve, according to any ofclaims 1 or 2, characterized in that the control mechanism (13) ispresent between the film (16) and the actuator.
 9. The valve, accordingto claim 8, characterized in that the control mechanism (13) is formedin whole or in part by an electroactive polymer according to claims 3through 8, or by a shape memory material (14), enabling the valve (52)to be activated or deactivated directly.
 10. The valve, according toeither claim 1 or 9, characterized in that the electroactive polymerconsists of a longitudinal strip of at least one layer of electroactivepolymer, or in that the shape memory material (14) consists of a wiremade of complex alloy whose structure changes according to thetemperature, such as a nickel and titanium alloy.
 11. The valve,according to any one of claims 8 through 10, characterized in that thememory shape material (14) cooperates with a rocking lever (15) which,together, form all or part of the control mechanism (13).
 12. The valve,according to claim 11, characterized in that the rocking lever (15)consists of a flexible part (18) and a rigid part (19), the rigid partco-operating with the compression means (8) of the valve (2), the shapememory material (14), the lever (I 5) and the compression means (8)together forming all or part of the control mechanism (13).
 13. A testsample card containing at least one valve, according to any of claims 1through
 12. 14. A process for activating a valve, according to any ofclaims 1 through 12, characterized in that it consists in: applying anelectric current to a film or an electro-active polymer wire or a shapememory metal in rest position, the valve being in open (or closed)position, maintaining the current to hold the film or wire in activeposition corresponding to a direct or indirect action on the valve inclosed (or open) position, and stopping the current so that said film orwire returns to rest position and said valve returns to open (or closed)position.